Physiologic and Behavioral Correlates of Energy Intake in Emerging Adulthood: Cross-Sectional Analysis of the RIGHT Track Health Study

Background: Consistent findings have reported that FFM is associated with EI. However, conjoint assessments of physiologic (body composition, fasting serum leptin) and behavioral [eating behaviors and physical activity (PA)] correlates of EI during emerging adulthood have not been examined. Objectives: We assessed associations between physiologic and behavioral correlates of EI within the context of one another in emerging adults (18-28 years old). We also assessed these associations in a subsample after the removal of probable EI underreporters. Methods: Cross-sectional data from 244 emerging adults (age = 19.6 +/- 1.4 y; BMI = 26.4 +/- 6.6 kg/m(2); 56.6% female) from the RIGHT Track Health study were used. Measures included body composition (BOD POD), eating behaviors (Three-Factor Eating Questionnaire), objective and subjective PA (accelerometer-derived total activity counts and Godin-Shephard Leisure-Time Exercise Questionnaire), fasting serum leptin, and EI (three 24-hour dietary recalls). Correlates independently associated with EI were entered into a backward stepwise linear regression model. Correlates that met the criteria of P < 0.05 were retained. Analyses were repeated in a subsample after removing probable EI underreporters (n = 48). Effect modification by sex (male and female) and BMI (BMI < 25 kg/m(2), BMI >= 25 kg/m(2)) categories was also assessed. Results: In the full sample, FFM (8: 18.4; 95% CI: 9.9, 26.8), leptin (8: -84.8; 95% CI: -154.3, -15.4), dietary restraint (8: -35.2; 95% CI: -59.1, -11.3), and subjective PA (8: 2.5; 95% CI: 0.04, 4.9) were significantly associated with EI. After the removal of probable under-reporters, only FFM remained significantly associated with EI (8: 43.9; 95% CI: 27.2, 60.6). No evidence of effect modification by sex or BMI categories was noted. Conclusions: Although physiologic and behavioral correlates were associated with EI in the full sample, only FFM remained a robust correlate of EI in a subsample of emerging adults after removing probable EI underreporters.